aggressive behaviour,red deer: stags competing during rutting seasonStefan Meyers GDT/Ardea Londonanimal behaviour that involves actual or potential harm to another animal. Biologists commonly distinguish between two types of aggressive behaviour: predatory or antipredatory aggression, in which animals prey upon or defend themselves from other animals of different species, and intraspecific aggression, in which animals attack members of their own species. Intraspecific aggression is widespread across the animal kingdom, being seen in creatures as diverse as sea anemones, rag worms, wolf spiders, field crickets, lobsters, salmon, tree frogs, lizards, songbirds, rats, and chimpanzees. Given that so many different kinds of animals fight, aggression takes a variety of forms. Sea anemones ... (100 of 5,568 words)